Ketamine - chronic neuralgic pain control

Can anyone supply me with information on the use of Ketamine in the control of
chronic neuralgic pain in the terminal stages of cancer.
I'm making this enquiry on behalf of St. Michael's Hospice, Hereford, England.
They have a patient who might possibly be helped
Any iformation would be gratefully appreciated.
Thanks in advance.
David Bowen
Hon. Chaplain